Detection of bovine meat adulteration by UV-VIS, NIR and MIR spectroscopy

Introduction: In recent years many investigators applied various techniques to identify meat species, but the development of an easy, rapid and sensitive method is still needed. The aim of this work was to investigate the potential of UV-VIS, NIR and MIR spectroscopy to detect bovine meat adulteration with turkey meat. The use of several chemometric techniques were explored to determine the effect on method sensitivity. Materials and Methods: Eleven different lots of beef and turkey meat from different animals were used. Each lot was separately minced and then used to prepare in duplicate 7 mixtures (450 g each) of bovine meat added with different percentages of turkey meat, ranging from 5 to 50%. The 154 mixtures thus obtained and the 44 meat samples of 100% beef and 100% turkey were analyzed by means of UV-VIS, NIR and MIR spectroscopy. The UV-VIS spectra (200-780 nm) were collected using an integrative sphere working in diffuse reflectance. The NIR and MIR spectra were recorded using an FT-NIR spectrometer (12500-3900 cm-1) and an FT-IR spectrometer equipped with an ATR cell (400-700 cm-1), respectively. The spectral data, standardized by different pretreatments, were processed using PCA and classification techniques (LDA, PLS-DA) applied after feature selection by the algorithm SELECT. Results and Discussion: For all spectroscopy techniques used, clusters have been identified in the PCA score plots obtained from spectra, that allowed distinction between adulterated and not-adulterated bovine meat. The best distinct percentages of adulteration were those ranging from 30 to 50%. Classification results showed that samples belonging to a particular adulteration level could be correctly classified. The most accurate results were obtained with either feature selection or data compression. Conclusion: The potential of UV-VIS, NIR, and MIR spectroscopy techniques to distinguish between adulterated and not-adulterated beef meat was demonstrated. Moreover, the use of chemometric strategies applied to fused UV-VIS, NIR and MIR spectra could represent an effective method for classification of bovine meat on the basis of adulteration level. Novelty statement: This study represents a significant basis for developing an easy, rapid and sensitive spectroscopic method to identify bovine meat adulteration with lower grade substitutes. Summary: UV-VIS, NIR and MIR spectroscopy techniques, combined with the suitable chemometric strategies, could be useful tools for the rapid and easy identification of bovine meat adulteration with lower grade substitutes, such as turkey.